Re: [Gumstix-users] Using 3 UARTS of GPSSTIX

[Dave H. <dhy...@gm...>]

Hi Tisham,

On Sun, Feb 14, 2010 at 7:54 AM, whatnick
<ti...@el...> wrote:
>
> Hi again,
>
> I have tested the ports with a scope and GPIO configuration to make sure
> they are indeed connected.
>
>  while(true);do echo "GPIO out set" > /proc/gpio/GPIO43;sleep 1;echo "GPIO
> out clear" > /proc/gpio/GPIO43;sleep 1;done
>
> Produces a 1s pulse on HWUART TXD and choosing GPIO42 does the same on
> HWUART RXD. So how do I go back from GPIO and get back a UART. I dont really
> want to bitbang the GPIO to achieve uart functionality.

Whether the HWUART is available or not, depends on which gumstix board
you have and which daughtercards you're using.

Also depending on the board combinations, sometimes its the BTUART
pins which are connected  to the HWUART pins. Since you've mentioned
GPIO 43, it sounds like BTUART.

To configure BTUART as a UART, use:

echo "AF1 in" > /proc/gpio/GPIO42 # BTRXD
echo "AF2 out" > /proc/gpio/GPIO43 # BTTXD
echo "AF1 in" > /proc/gpio/GPIO44   # BTCTS
echo "AF2 out" > /proc/gpio/GPIO45 # BTRTS

This is from:
<http://docwiki.gumstix.com/index.php/Gumstix_UARTs>

-- 
Dave Hylands
Shuswap, BC, Canada
http://www.DaveHylands.com/